Advances in Virally Templated Flexible Batteries

February 23, 2010

Stamped lightweight flexible batteries: Batteries were constructed from genetically-engineered templates. The diameter of the battery shown on the right is 3mm (i.e., three one-thousands of a millimeter).

Researchers sponsored by the Army Research Laboratory through the Institute for Collaborative Biotechnologies (ICB) have pioneered the use of biological systems to engineer batteries. The research team has used genetically engineered bacterial viruses as templates for semiconductors and metals in controlled arrays, creating uniquely efficient, micro-scale batteries for Soldier personal power. Professor Angela Belcher, located at the Massachusetts Institute of Technology, is working with ARL and is focused on customizing the batteries for Army applications.

Most lithium-ion batteries are relatively bulky and must be enclosed within a hard, inflexible shell. The new batteries are lighter, retain their charge longer, and are more flexible when compared to existing lithium-ion batteries.

In this revolutionary route to thin-film, conformable batteries, genetically engineered phage were used to synthesize and assemble hybrid nanowires of cobalt oxide and gold at room temperature. Combining this virus-templated synthesis with a two-dimensional controlled assembly of the virus's electrolyte layers provided a systematic platform for integrating the nanomaterials to form thin, flexible lithium-ion batteries. Performance measurements indicate that the batteries have a capacity three times higher than that of currently available lithium-ion rechargeable batteries. The weight of a 10 cm x 10 cm transparent, flexible, self-assembled cobalt oxide-based battery made by this method is only 30 mg - an additional advantage over previous lithium-ion batteries. Collectively, the new improvements will lead to light and flexible power sources for the Soldier in the field.

Over the past year, a number of new electrode and electrolyte combinations were explored and the batteries were further optimized. In addition, many promising extensions of this technology began, including an integration of the batteries and the formation of methods concerning the development of ultra-capacitors, radio frequency identification (RFID) devices, and catalysts for the production of hydrogen fuel from water.